Gatling type guns, having a plurality of gun barrels disposed in an annular row in a rotor for rotation in a housing, are well known, having been first disclosed in U.S. Pat. No. 36,836 issued Nov. 4, 1862 to R. J. Gatling. The early Gatling guns had manual crank drives. C. J. Ebbets in U.S. Pat. No. 550,262 issued Nov. 26, 1895, and W. E. Simpson in U.S. Pat. No. 598,822 issued Feb. 8, 1898, respectively disclose supplemental gas drives wherein gun gas is bled from a port in the side of each barrel to operate a ratchet drive for the rotor. The modern Gatling gun was first disclosed in U.S. Pat. No. 2,849,921 issued Sept. 2, 1958 to H. Otto which had an electric motor drive.
Muzzle brakes for single barrel guns are also well known and are shown, for example, in U.S. Pat. No. 1,994,458 issued Mar. 19, 1935 to G. M. Barnes; U.S. Pat. No. 2,457,802 issued Jan. 4, 1949 to A. Bauer; and U.S. Pat. No. 2,567,826 issued Sept. 11, 1951 to J. E. Prache.
Muzzle brake torque assist devices for Gatling guns are shown in U.S. Pat. No. 3,703,122 issued Nov. 21, 1972 to D. A. Farrington et al, and U.S. Pat. No. 3,898,910 issued Aug. 12, 1975 to R. T. Groff. These patents respectively disclose a single turbine having a single annular row of curved radial passageways. Since each of the plurality of gun barrels in the rotor respectively provides gas mainly to the adjacent portion or sector of radial passageways; there is a lateral load which must be reacted by the stationary structure at the radius of the turbine outlets to react the force generated at the turbine outlets. The diameter of the single turbine must be larger than the diameter of the annular row of gun barrels, since the outlets of the single turbine are disposed radially outwardly beyond the maximum radius of the row of barrels.